Abstract: This paper reports a case of adolescent secondary syphilis with purpura as the initial manifestation. A 15-year-old female presented with a 1-day history of petechiae and ecchymoses on both lower extremities. She was initially diagnosed with Henoch-Schnlein purpura. Approximately 5 hours after treatment with piperacillin sodium, she developed chills, high fever, and a significant aggravation of the purpura on both lower extremities, followed by the appearance of copper-red maculopapular rashes on the palms and soles. Further history taking revealed unprotected sexual exposure 1 month earlier. Syphilis serological tests showed a TRUST titer of 1∶32 and a positive TPPA result, confirming the diagnosis of secondary syphilis. After anti-syphilis treatment with benzathine penicillin for 9 months, the skin lesions subsided and the serological titer turned negative.

Key words: secondary syphilis, purpura, adolescent, Jarisch-Herxheimer reaction